1. Field of the Invention
The invention relates to a data security system for a navigation system and to a method for transmitting navigation data from a data memory to a data storage unit of a navigation system.
2. Related Art
Navigation systems are available that provide users, such as drivers when the navigation systems are installed in vehicles, with various navigation functions and features. These navigation systems can determine a route from a specified starting location to a certain destination and can guide a traveler along this route. The navigation system may then provide the user with information about the optimal route to the destination in the form of instructions that identify the maneuvers required for the user to travel from the present location to the destination location.
To provide these navigation functions and other functions, the navigation system uses detailed data bases comprising map data that represent physical features in a geographic region, these data bases including data representing the roads and intersection in a geographic region. The data bases may also include information about turn restrictions at intersections, speed limits along the roads, street names of the various roads, points of interest (“POI”), information about monuments, hotels, restaurant, and so on. These navigation data bases are normally provided on a data memory, e.g., a CD-ROM disk that is inserted into the navigation system. Recently, the use of fixed disks or hard disks permanently arranged in the navigation system has become popular.
However, after a certain amount of time, the information in the navigation data bases that form the basis for calculating a route to the destination location may need to be updated because the data may no longer correspond to the actual conditions in the geographic region. For example, routes may have changed or new streets may have been built, or street names or POI data may have changed since the creation of the navigation data base. When a CD-ROM disk is used, the user gets a new CD-ROM disk containing the new data. In the case of a hard disk or fixed disk, the user is provided with a data memory containing the new updated navigation data that have to be transmitted to the fixed disk of the navigation system. When the navigation data have been transmitted to the hard disk of the navigation system, the data memory is no longer necessary for the functioning of the navigation programs. As a consequence, the data memory with the updated data may be used several times to update several different navigation systems. However, this is normally prohibited by applicable law or by contractual obligation, because, when buying the update navigation data base, the user is only allowed to use the updated data on one navigation system or on one vehicle.
Therefore, a need exists to ensure that update navigation data to be transmitted to a fixed disk of a navigation system may only be used according to applicable law or contractual obligation, and that any data transfer to the fixed disk of the navigation system may be controlled so as to achieve this objective.